JP7156565B1 - MOTOR DRIVING DEVICE, MOTOR DRIVING METHOD, AND MOTOR DRIVING PROGRAM - Google Patents

Abstract

A motor drive device with a reduced number of current sensors is provided. A first drive section for driving a plurality of first motor phases of a first motor; a second drive section for driving a plurality of second motor phases of a second motor; a common sensor for detecting a total current flowing through a phase pair selected one by one from the second motor phase of each of the plurality of first motor phases; one first motor phase sensor, at least one second motor phase sensor for detecting current flowing in each of the plurality of second motor phases that are not included in a phase pair, a common sensor, and at least one first motor phase sensor. driving amounts of the plurality of first motor phases and the plurality of second motor phases by the first drive unit and the second drive unit using respective current detection values of the motor phase sensor and the at least one second motor phase sensor; and a drive controller for controlling a motor drive device. [Selection drawing] Fig. 5

Description

The present invention relates to a motor driving device, a motor driving method, and a motor driving program.

In Patent Document 1, "A current sensor 30u for detecting a three-phase current (U-phase, V-phase, W-phase) supplied from the inverter 14 to the brushless DC motor 10 is provided between the inverter 14 and the brushless DC motor 10. , 30v and 30w are provided” (paragraph 0012), “The current sensor failure diagnosis unit 23 time-averages the current values for one cycle of each of the U, V, and W phases, and the average value becomes zero. It is also possible to determine that the current sensor is faulty when the signal from the current sensor 30 is open or short-circuited, or the current sensor 30 is faulty. may be used” (paragraph 0019), “On the other hand, when the current sensor failure diagnosis unit 23 detects an abnormality in the current sensor 30u, an alarm is first issued (step S5 ).Furthermore, the inverter control is switched to the inverter control using the detected values iv and iw of the current sensors 30v and 30w and the estimated current value iua obtained from the detected values iv and iw (step S6)” (paragraph 0023). It is

In Patent Document 2, “In this example, two inverters and two motors are provided. A motor M2 is connected to 16. The configuration of this inverter 16 is the same as that of the inverter 14, and the coil ends of each phase of the inverter M2 are connected to the midpoints of the arms of each phase of the inverter 16. Also, the motor current of each phase of the motor 16 is detected by the current sensor 28 and supplied to the control device 30" (page 10, lines 23-29).
[Prior art documents]
[Patent Literature]
[Patent Document 1] JP-A-2008-022645 [Patent Document 2] International Publication No. 2003-015254

In Patent Documents 1 and 2, it is necessary to provide a current sensor for each phase of the motor. When using a plurality of motors as in Patent Document 2, it is necessary to provide a current sensor for each phase of each of the plurality of motors.

In a first aspect of the invention, a motor drive is provided. The motor drive device may include a first drive section that drives a plurality of first motor phases of the first motor. The motor drive device may include a second drive section that drives a plurality of second motor phases of the second motor. The motor drive device may include a common sensor that detects a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases. The motor driving device may comprise at least one first motor phase sensor that detects current flowing in each phase of the plurality of first motor phases that is not included in the phase pair. The motor driving device may comprise at least one second motor phase sensor for detecting current flowing in each of the plurality of second motor phases that are not included in the phase pair. The motor driving device uses current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor to operate the first driving section and the second driving section. A drive control section may be provided for controlling the drive amounts of the plurality of first motor phases and the plurality of second motor phases.

In response to detection of a failure of one of the at least one first motor phase sensor and the at least one second motor phase sensor, the drive control unit controls the one of the at least one first motor phase sensor and the at least one second motor phase sensor. using a result of estimating a current detection value of a sensor using current detection values of other sensors among the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor; Driving amounts of the plurality of first motor phases and the plurality of second motor phases by the first driving section and the second driving section may be controlled.

The drive control unit calculates the first motor and the second motor using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor. a failure detection unit that detects that any sensor has failed in response to the total amount of current flowing into the is outside the range of 0 to a predetermined error.

Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. can flow. The drive control unit detects that one of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor has failed, and Calculated using the current detection value of the at least one second motor phase sensor and the first current vector calculated using the current detection value of the at least one first motor phase sensor in the winding short circuit state of the second motor and a common sensor failure identifying unit that identifies that the common sensor has failed when a difference in magnitude from the second current vector obtained is within a predetermined error range.

The drive control unit calculates the first motor phase using current detection values of the common sensor and the at least one second motor phase sensor in a state in which the plurality of first motor phases of the first motor are open. a first sensor group failure diagnosis unit for diagnosing that the at least one second motor phase sensor is normal when the total amount of current flowing into the two motors is within a predetermined error range from 0; may have

The drive control unit calculates the current detection value of each of the common sensor and the at least one first motor phase sensor while the plurality of second motor phases of the second motor are open. a second sensor group failure diagnosis unit for diagnosing that the at least one first motor phase sensor is normal when the total amount of current flowing into the two motors is within a predetermined error range from 0; may have

In the first motor and the second motor, when the windings are short-circuited, the difference between the magnitudes of the first current vector and the second current vector obtained by converting the phase currents of the respective phases is within a predetermined error range. current can flow. The drive control unit, in response to the diagnosis that one of the at least one first motor phase sensor has failed, in a winding short circuit state of the first motor and the second motor, The current detection value of the common sensor and the current detection of each of the at least one first motor phase sensor at the timing when it is determined that the current flowing through the phase included in the phase pair among the plurality of second motor phases becomes 0. It may have a current vector calculator that calculates at least one of the first current vectors using the values. The drive control unit maximizes a difference in magnitude between the at least one first current vector and the second current vector calculated using the current detection value of the at least one second motor phase sensor. A first sensor failure identification unit may be provided for identifying that the first motor phase sensor that has output the current detection value used to calculate the first current vector has failed.

The plurality of first motor phases may be three first motor phases. The plurality of second motor phases may be three second motor phases. The number of common sensors may be one. The at least one first motor phase sensor may be two first motor phase sensors. The at least one second motor phase sensor may be two second motor phase sensors.

A second aspect of the present invention provides a motor driving method. The motor driving method may comprise the first driving section driving a plurality of first motor phases of the first motor. The motor driving method may comprise the second driving section driving a plurality of second motor phases of the second motor. The motor driving method may comprise a common sensor detecting a total current flowing through phase pairs selected one by one from the plurality of first motor phases and the plurality of second motor phases. The motor driving method may comprise at least one first motor phase sensor respectively detecting current flowing through each phase of the plurality of first motor phases not included in the phase pair. The motor driving method may comprise at least one second motor phase sensor respectively detecting current flowing through each phase of the plurality of second motor phases not included in the phase pair. In the motor driving method, the drive control section uses current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor to control the first drive section and the It may comprise controlling the drive amount of the plurality of first motor phases and the plurality of second motor phases by the second driving section.

A third aspect of the present invention provides a motor drive program for execution by a computer. The motor driving program may cause the computer to function as a first driving section that drives a plurality of first motor phases of the first motor. The motor driving program may cause the computer to function as a second driving section that drives a plurality of second motor phases of a second motor. A motor driving program causes the computer to control a common sensor for detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases, the plurality of first motors. at least one first motor phase sensor respectively detecting current flowing through each of the phases not included in the phase pair; and current flowing through each of the plurality of second motor phases not included in the phase pair. of the plurality of first motor phases and the plurality of second motor phases by the first drive section and the second drive section using current detection values of at least one second motor phase sensor that respectively detects It may function as a drive control section that controls the drive amount.

It should be noted that the above summary of the invention does not list all the features of the invention. Subcombinations of these feature groups can also be inventions.

1 shows the configuration of a drive system 10 according to this embodiment. 2 shows the configuration of drive units 110-1 and 110-2 and the form of connection with motors M1 and M2 in the drive system 10 according to the present embodiment. An example of the structure of sensor S1 which concerns on this embodiment is shown. An example of the structure of sensor S5 which concerns on this embodiment is shown. 3 shows the configuration of a drive control unit 120 according to the embodiment; 4 shows an operation flow of the failure detection unit 500 according to the embodiment. 4 shows an operational flow of a common sensor failure identification unit 520 according to the present embodiment; An example of waveforms of phase currents flowing in motors M1-M2 is shown. 4 shows an operation flow of the first sensor group failure diagnosis section 530 according to the present embodiment. 4 shows an operation flow of the first sensor failure identification unit 540 according to the present embodiment; 3 shows the operation flow of current vector calculation unit 510, current command calculation units 570-1 and 570-2, and current control units 580-1 and 580-2 according to the present embodiment. 3 shows a configuration of part of a drive control unit 1220 according to a modification of the embodiment; An example computer 2200 is shown in which aspects of the present invention may be embodied in whole or in part.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

FIG. 1 shows the configuration of a drive system 10 according to this embodiment. A drive system 10 according to the present embodiment detects the total current flowing through a specific phase in each of a plurality of motors using a common current sensor. As a result, drive system 10 can reduce the number of current sensors compared to a case where current sensors are individually provided for all phases of each motor.

The drive system 10 includes a plurality of motors M1-2, a plurality of current sensors S1-5 (also referred to as "a plurality of sensors S1-5"), a plurality of rotation angle sensors R1-2, and a motor drive device 100. Prepare. Each of the plurality of motors M1-M2 may be a synchronous motor or a permanent magnet (PM) motor. In the example of this figure, the drive system 10 comprises two motors M1-2. Motor M1 is an example of a "first motor" and has a plurality of phases (also referred to as "first motor phases"). Motor M2 is an example of a "second motor" and has a plurality of phases (also referred to as "second motor phases"). In this embodiment, the plurality of first motor phases are three first motor phases and the plurality of second motor phases are three second motor phases.

Alternatively, drive system 10 may include a different number of motors and may have motors with different numbers of phases. Each of the motors M1 and M2 has coils for each phase that are connected to each other at the midpoint, and rotates according to the AC current input to each phase.

Each of the plurality of sensors S1-5 detects the current flowing through each phase of the plurality of motors M1-M2. The plurality of sensors S1-5 include a common sensor S5 that detects the total current flowing through phase pairs selected one by one from the plurality of first motor phases and the plurality of second motor phases. In this embodiment, the number of common sensors is one. The current sensor S5 detects one phase (W phase) from three first motor phases (U, V, and W phases of motor M1) and one phase from three second motor phases (U, V, and W phases of motor M2). A total current iw12 flowing through each selected phase pair (a W-phase pair of the motor M1 and a W-phase pair of the motor M2) is detected.

Also, the plurality of current sensors includes at least one first motor phase sensor that detects a current flowing through each phase of the plurality of first motor phases that is not included in the phase pair. In the example of this figure, the at least one first motor phase sensor is two first motor phase sensors and the at least one second motor phase sensor is two second motor phase sensors. Drive system 10 includes current sensors S1 and S2 that respectively detect currents iu1 and iv1 flowing through U and V phases that are not included in a phase pair (a pair of W phases of motors M1 and M2) among the three phases of motor M1. including. Drive system 10 also includes current sensors S3 and S4 that respectively detect currents iu2 and iv2 flowing through U and V phases that are not included in a phase pair among the three phases of motor M2.

Thus, in the example of this figure, the common current sensor S5 is provided for the W-phase pair of the motors M1 to M2, and individual current sensors are not provided. Therefore, the number of current sensors can be reduced compared to the case where current sensors are individually provided for the W phase of motor M1 and the W phase of motor M2.

Each of the plurality of rotation angle sensors R1-2 is provided corresponding to each of the plurality of motors M1-M2. In the example of this figure, the rotation angle sensor R1 detects the rotation angle θ1 of the motor M1. A rotation angle sensor R2 detects a rotation angle θ2 of the motor M2. The rotation angle sensors R1-2 may detect mechanical angles of the motors M1-2 and output them as rotation angles θ1-2.

Motor driving device 100 is connected to a plurality of motors M1-2, a plurality of current sensors S1-5, and a plurality of rotation angle sensors R1-2. The motor driving device 100 drives each phase of each motor according to command values τ1-2 such as a torque command to each motor input from an external device or the like. The motor drive device 100 has a plurality of drive units 110-1 to 2 (also referred to as “drive units 110”) and a drive control unit 120. FIG.

Each of the plurality of drive units 110-1 to 110-2 is provided corresponding to each of the plurality of motors M1 to M2, and drives each phase of the corresponding motor. Drive unit 110-1 is an example of a “first drive unit” and drives a plurality of first motor phases (U, V, W phases) of first motor M1. Drive unit 110-2 is an example of a “second drive unit” and drives a plurality of second motor phases (U, V, W phases) of second motor M2.

Drive control unit 120 outputs command values τ1-2, detection values of currents iu1, iv1, iu2, iv2, and iw12 detected by current sensors S1-5, and rotation angle θ1 detected by rotation angle sensors R1-2. Enter a detection value of ~2. Drive control unit 120 uses these inputs to control the drive amounts of U, V, and W phases of motor M1 and U, V, and W phases of motor M2 by drive units 110-1 and 110-2. . The drive control unit 120 supplies control signals Gu1 to Gz1 for controlling the upper and lower arms of the U, V, and W phases of the motor M1 to the drive unit 110-1, thereby controlling the drive amount of each phase of the motor M1. do. Further, the drive control unit 120 supplies control signals Gu2 to Gz2 for controlling the upper and lower arms of the U, V, and W phases of the motor M2 to the drive unit 110-2, thereby controlling the drive amount of each phase of the motor M2. to control.

Further, drive control section 120 outputs control signal SH1 to drive section 110-1, and outputs control signal SH2 to drive section 110-2. The drive control unit 120 can use the control signals SH1-SH2 to instruct the corresponding motors M1-M2 to short-circuit or open the windings.

FIG. 2 shows the configuration of the driving units 110-1 and 110-2 and the form of connection with the motors M1 and M2 in the driving system 10 according to this embodiment. Drive units 110-1 and 110-2 convert a DC voltage supplied from a power supply Vdc provided between the positive and negative DC bus lines into an AC voltage (three-phase AC voltage in this embodiment) for driving motors M1 and M2. voltage) and supplied to the motors M1-2.

Drive unit 110-1 provides a plurality of upper-arm switching elements u1, v1, and w1 and a plurality of lower-arm switching elements x1, y1, and z1, respectively, corresponding to the respective phases of motor M1. have Each upper arm side switching element and each lower arm side switching element may be a power semiconductor element, for example, an IGBT (insulated gate bipolar transistor) having a collector and an emitter as main terminals and a gate as a control terminal. be. Alternatively, each upper arm switching element and each lower arm switching element may be a MOSFET having a drain and a source as main terminals and a gate as a control terminal.

The upper arm switching element u1 and the lower arm switching element x1 are connected between the main terminals in this order in parallel with the power source Vdc between the positive DC bus and the negative DC bus. A first phase terminal (U-phase terminal) of the motor M1 is connected between the lower arm side switching element x1. The upper arm switching element v1 and the lower arm switching element y1, and the upper arm switching element w1 and the lower arm switching element z1 are connected between the DC bus lines similarly to the upper arm switching element u1 and the lower arm switching element x1. between the upper arm side switching element v1 and the lower arm side switching element y1, the second phase terminal (V-phase terminal) of the motor M1, the upper arm side switching element w1 and the lower arm side switching element z1 A third phase terminal (W phase terminal) of the motor M1 is connected between .

Each upper arm side switching element and each lower arm side switching element may have a freewheel diode reversely connected to the switching element body. Here, when each upper arm side switching element and each lower arm side switching element is a MOSFET, the freewheel diode may be a parasitic diode.

Further, the drive section 110-1 has a short circuit control section 200-1 and a gate driver 210-1. The short-circuit control unit 200-1 generates control signals Gu1a to Gz1a obtained by controlling the control signals Gu1 to Gz1 from the drive control unit 120 to short-circuit or open the windings of the motor M1 according to the control signal SH1. Output. When the control signal SH1 instructs winding short-circuiting, the gate driver 210-1 sets the control signals Gu1a to Gw1a to logic L (low level) and the control signals Gx1a to Gz1a to logic H (high level). As a result, the short-circuit control unit 200-1 forcibly turns off the upper arm side switching elements u1 to w1 and forcibly turns on the lower arm side switching elements x1 to z1, thereby forcibly turning on the lower arm side switching elements x1 to z1. All phases of motor M1 are short-circuited. Alternatively, the short circuit control section 200-1 may forcibly turn on the upper arm side switching elements u1 to w1 and forcibly turn off the lower arm side switching elements x1 to z1 when the windings are short-circuited.

When the control signal SH1 instructs to open the winding, the short circuit control section 200-1 sets the control signals Gu1a to Gz1a to logic L. As a result, the gate driver 210-1 forcibly turns off all the switching elements u1 to z1 and opens all the phases of the motor M1.

The gate driver 210-1 outputs control signals Gu1b to Gz1b obtained by amplifying the control signals Gu1a to Gz1a. Control signals Gu1b, Gv1b, and Gw1b are supplied to the control terminals of the upper arm side switching elements u1, v1, and w1. Control signals Gx1b, Gy1b, and Gz1b are supplied to the control terminals of the lower arm side switching elements x1, y1, and z1.

Drive unit 110-2 provides a plurality of upper-arm switching elements u2, v2, and w2 and a plurality of lower-arm switching elements x2, y2, and z2, respectively, corresponding to the respective phases of motor M2. have The switching elements u2 to z2 are the same as the switching elements u1 to z1 except that they are used to drive the motor M2, so the description thereof will be omitted.

Further, the drive section 110-2 has a short circuit control section 200-2 and a gate driver 210-2. Short-circuit control unit 200-2, like short-circuit control unit 200-1, responds to control signals Gu2 to Gz2 from drive control unit 120 and short-circuits or opens windings of motor M2 according to control signal SH2. It outputs control signals Gu2a to Gz2a to which control has been applied. The gate driver 210-2 outputs control signals Gu2b to Gz2b obtained by amplifying the control signals Gu2a to Gz2a, similarly to the gate driver 210-1. Control signals Gu2b, Gv2b, and Gw2b are supplied to the control terminals of the upper-arm switching elements u2, v2, and w2. Control signals Gx2b, Gy2b, and Gz2b are supplied to the control terminals of the lower arm side switching elements x2, y2, and z2.

FIG. 3 shows an example of the structure of the sensor S1 according to this embodiment. Sensor S1 is provided on conductor 300, which is wiring connecting between the midpoint of upper-arm switching element u1 and lower-arm switching element x1 of drive unit 110-1 and the U phase of motor M1. Sensor S1 includes magnetic core 310 and magnetic sensor 320 .

The magnetic core 310 is an annular soft magnetic body that surrounds the conductor 300 at a specific location on the conductor 300 . The magnetic core 310 focuses a spiral magnetic field generated around the conductor 300 according to the current flowing through the conductor 300 . The magnetic sensor 320 is arranged in a gap provided at a specific position on the circumference of the magnetic core 310 and outputs a detected value corresponding to the strength of the magnetic field focused by the magnetic core 310 as a current detected value. Sensors S2-S4 may have similar functions and configurations as sensor S1.

FIG. 4 shows an example of the structure of the sensor S5 according to this embodiment. A first conductor 400 in the drawing is a wiring that connects between the midpoint of the upper arm side switching element w1 and the lower arm side switching element z1 of the driving section 110-1 and the W phase of the motor M1. The second conductor 405 is a wiring that connects between the midpoint of the upper arm side switching element w2 and the lower arm side switching element z2 of the driving section 110-2 and the W phase of the motor M2. The first conductor 400 and the second conductor 405 run close together and substantially parallel at the location where the sensor S5 is provided.

Sensor S5 includes magnetic core 410 and magnetic sensor 420 . The magnetic core 410 is an annular soft magnetic body surrounding the outer periphery of the set of the first conductor 400 and the second conductor 405 . The magnetic core 410 focuses the spiral magnetic field generated around the first conductor 400 and the second conductor 405 according to the sum of the currents flowing through the first conductor 400 and the second conductor 405 . The magnetic sensor 420 is arranged in a gap provided at a specific position on the circumference of the magnetic core 410 and outputs a detected value corresponding to the strength of the magnetic field focused by the magnetic core 410 as a current detected value. As a result, the sensor S5 uses one magnetic core and one magnetic sensor to generate a current iw12 (= iw1+iw2) can be detected.

FIG. 5 shows the configuration of the drive control unit 120 according to this embodiment. The drive control unit 120 may be realized by causing a CPU such as a motor control microcontroller or processor, or a computer including a CPU, to execute a motor drive program. Alternatively, the drive control section 120 may be realized by a hardware circuit.

In this embodiment, the drive control unit 120 identifies the failed sensor for a single failure of the plurality of sensors S1 to S5 (that is, failure of one of the sensors), and detects the current detection value of the sensors other than the failed sensor. It is possible to continue driving the motors M1 to M2 by using. The drive control unit 120 includes a failure detection unit 500, a current vector calculation unit 510, a common sensor failure identification unit 520, a first sensor group failure diagnosis unit 530, a first sensor failure identification unit 540, and a second sensor failure detection unit. A specifying unit 550, a plurality of current command calculation units 570-1 and 570-2 (also referred to as “current command calculation units 570”), and a plurality of current control units 580-1 and 2 (also referred to as “current control units 580”). ) and

The failure detection unit 500 inputs current detection values iu1, iv1, iu2, iv2, and iw12 of the plurality of sensors S1-5. The failure detection unit 500 uses these current detection values to detect whether or not any of the plurality of sensors S1 to S5 has failed. A specific operation of the failure detection unit 500 will be described later with reference to FIG.

Current vector calculation unit 510 receives current detection values iu1, iv1, iu2, iv2, and iw12 from a plurality of sensors S1-5 and rotation angle detection values θ1-2 from rotation angle sensors R1-2. Current vector calculation unit 510 uses these detection values to calculate a plurality of current vectors used for failure diagnosis of sensors S1-5 and a plurality of current vectors used for drive control of motors M1-2. .

Common sensor failure identification section 520 is connected to failure detection section 500 and current vector calculation section 510 . Common sensor failure identification unit 520 uses a current vector for failure diagnosis input from current vector calculation unit 510 in response to detection of a failure in one of the sensors by failure detection unit 500, and detects common sensor S5. Determine if it is faulty. A specific operation of the common sensor failure identification unit 520 will be described later using FIG.

The first sensor group failure diagnosis section 530 is connected to the common sensor failure identification section 520 . The first sensor group failure diagnosis section 530 receives current detection values of the plurality of sensors S1 to S5. First sensor group failure diagnosis section 530 uses these current detection values to determine whether one of first motor phase sensors S1-2 (sensors of the first sensor group) A diagnosis is made as to whether or not any one of the two motor phase sensors S3-4 (sensors of the second sensor group) has failed. A specific operation of the first sensor group failure diagnosis section 530 will be described later with reference to FIG.

First sensor failure identification section 540 is connected to current vector calculation section 510 and first sensor group failure diagnosis section 530 . First sensor failure identification unit 540 detects current vector calculation unit 510 in response to first sensor group failure diagnosis unit 530 diagnosing that one of first motor phase sensors S1-2 is defective. A faulty sensor among the first motor phase sensors S1 to S2 is identified using the current vector for fault diagnosis input from . A specific operation of first sensor failure identifying section 540 will be described later with reference to FIG.

Second sensor failure identification section 550 is connected to current vector calculation section 510 and first sensor group failure diagnosis section 530 . Second sensor failure identification unit 550 detects current vector calculation unit 510 in response to first sensor group failure diagnosis unit 530 diagnosing that one of second motor phase sensors S3 to S4 has failed. A faulty sensor among the second motor phase sensors S3 to S4 is identified by using the current vector for fault diagnosis input from S3 to S4. A specific operation of the second sensor failure identifying section 550 is the same as that of the first sensor failure identifying section 540, which will be described later with reference to FIG.

Each of the plurality of current command calculation units 570 is provided corresponding to each of the plurality of motors M1-M2. A current command calculation unit 570-1 inputs the rotation angle detection value θ1 of the motor M1 and the torque command value τ1 that specifies the torque for driving the motor M1, and calculates a vector format from the rotation angle detection value θ1 and the torque command value τ1. current command value I1t (=(I1td, I1tq)). A current command calculation unit 570-2 inputs a rotation angle detection value θ2 of the motor M2 and a torque command value τ2 that specifies the torque for driving the motor M2, and generates a vector format from the rotation angle detection value θ2 and the torque command value τ2. A current command value I2t (=(I2td, I2tq)) is generated.

Each of the plurality of current control units 580 is provided corresponding to each of the plurality of motors M1-M2. Current control unit 580-1 detects rotation angle θ1 of motor M1, current command value I1t (=(I1td, I1tq)) from current command calculation unit 570-1, and current vector calculation unit 510. , a current vector I1 (=(I1d, I1q)), which is a current detection value obtained by converting the phase current detection value of the motor M1 into a rotating coordinate system, is input, and the current vector I1 is brought close to (or matched with) the current command value I1t. ) to generate drive signals Gu1 to Gz1. The current control unit 580-1 supplies the generated drive signals Gu1 to Gz1 to the drive unit 110-1.

Current control unit 580-2 receives rotation angle detection value θ2 of motor M2, current command value I2t (=(I2td, I2tq)) from current command calculation unit 570-2, and current vector calculation unit 510. , a current vector I2 (=(I2d, I2q)), which is a current detection value obtained by converting the phase current detection value of the motor M2 into a rotating coordinate system, is input, and the current vector I2 is brought close to (or coincides with) the current command value I2t. ) to generate drive signals Gu2 to Gz2. The current control section 580-2 supplies the generated drive signals Gu2 to Gz2 to the drive section 110-2.

FIG. 6 shows the operation flow of the failure detection unit 500 according to this embodiment. In S600, the failure detection unit 500 detects current detection values (iw12, iu1, iv1, iu2, and iv2 ) to determine whether or not the total amount of current I _total flowing into the first motor M1 and the second motor M2 is approximately zero.

Here, since each of the motors M1 to M2 does not have a current input/output path other than the terminals of each phase, the amount of current flowing into each motor from the terminals of all phases (minus current amount in the case of outflow) is theoretically 0. Therefore, the total amount of current I _total =iu1+iv1+iu2+iv2+iw12 flowing into the plurality of motors M1-2 detected by the plurality of sensors S1-S5 is theoretically zero. However, since the plurality of sensors S1 to S5 actually have measurement errors, the total current amount I _total does not necessarily match 0 and has a certain amount of error. Therefore, the failure detection unit 500 determines whether or not the total current amount I _total is within the range of 0 to a predetermined error (allowable error) (within the range of 0±allowable error Δ _total ).

In S610, the failure detection unit 500 detects that one of the sensors has failed in response to the fact that the total amount of current I _total is outside the range of a predetermined allowable error from 0 (“Y” in S600). . If any one of the sensors S1 to S5 is faulty, the current detection value of the faulty sensor is different from the original value, so the total current amount I _total deviates from zero. Therefore, the failure detection unit 500 can detect that one of the sensors has failed when the total current amount I _total deviates from 0 (out of the range of the allowable error Δ _total from 0). can. If the total amount of current I _total is within the allowable error range from 0 (“N” in S600), the fault detector 500 advances the process to S600 to continue fault occurrence monitoring.

According to the failure detection unit 500 described above, even if current sensors are not provided for all phases of all motors, the total current flowing through the phase pairs selected one by one from each motor is detected. Current sensing from a common sensor can be used to detect that any sensor has failed. Note that the failure detection unit 500 may detect a failure when the total current amount I _total deviates from 0 momentarily. Alternatively, the failure detection unit 500 continues for a predetermined period (for example, a period of less than 1/2 of the minimum period corresponding to the maximum frequency of the phase current) so that the total current amount I _total A failure may be detected according to the detachment. Note that even when there are two or more common sensors, the failure detection unit 500 may detect that one of the sensors has failed using the operation flow shown in FIG.

FIG. 7 shows the operation flow of the common sensor failure identification unit 520 according to this embodiment. In the operation flow of FIG. 7, the common sensor failure identification unit 520 assumes that the plurality of motors M1 to M2 of the drive system 10 flow phase currents of substantially the same magnitude (amplitude) (however, even if the phases are out of Good), identify the failure of the common sensor S5. For example, the drive system 10 includes the motors M1 and M2 of the same type and used for rotating the same shaft (rotation of both left and right wheels of a vehicle, etc.), and the motors M1 and M2 of the same type and being the same. Examples include those used for rotating different axes of vehicles and the like.

In S700, common sensor failure identifying section 520 uses control signals SH1 and SH2 to instruct driving sections 110-1 and 110-2 to place a plurality of motors M1 and M2 in the winding short circuit state. Motor M1 and motor M2 flow phase currents in which the magnitude difference between the first current vector and the second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuit state.

In S710, the common sensor failure identification unit 520 waits for a predetermined period. As a result, common sensor failure identifying section 520 waits until the phase currents of motors M1 and M2 reach a steady state due to winding short circuit.

In S720, current vector calculation unit 510 calculates magnitude |I1(u1, v1 )| In other words, the current vector calculation unit 510 calculates the first current vector using the current detection value of each phase other than the phase in which the common sensor S5 is provided among the plurality of phases of the motor M1, and calculates the first current vector. Computes the magnitude of a vector. Note that the notation of I1(u1, v1) is the current detection value iu1 of the current sensor S1 provided in the U phase (u1) of the motor M1 and the current detection value iu1 of the current sensor S2 provided in the V phase (v1) of the motor M1. It means a current vector obtained by transforming the phase current of the motor M1 into a rotating coordinate system, which is calculated using the value iv1.

Current vector calculation unit 510 calculates a first current vector I1 (u1, v1) by dq transforming a set iu1, iv1, and iw1 of phase currents of motor M1. Since the total current flowing into the motor M1 is 0, the current vector calculator 510 does not use the W-phase current detection value as iw1=-iu1-iv1 in the calculation of the first current vector I1 (u1, v1). .

ここで、Ｉ１ｄおよびＩ１ｑは第１電流ベクトルＩ１（ｕ１，ｖ１）のｄ軸成分およびｑ軸成分、θはモータＭ１の回転角検出値θ１を電気角に変換した値である。 Formula (1) is a formula for calculating the first current vector I1(u1, v1) when the motor M1 has three phases.

Here, I1d and I1q are the d-axis component and q-axis component of the first current vector I1(u1, v1), and θ is a value obtained by converting the rotation angle detection value θ1 of the motor M1 into an electrical angle.

Current vector calculation section 510 calculates the magnitude |I1(u1, v1)| of the first current vector using Equation (2).

ここで、Ｉ２ｄおよびＩ２ｑは第２電流ベクトルＩ２（ｕ２，ｖ２）のｄ軸成分およびｑ軸成分、θはモータＭ２の回転角検出値θ２を電気角に変換した値である。 In S730, the current vector calculation unit 510 calculates the currents of the second motor phase sensors S3 to S4 when the windings of the motor M2 are short-circuited, as in the case of calculating the magnitude |I1(u1, v1)| of the first current vector. The magnitude |I2(u2, v2)| of the second current vector is calculated using the detected values iu2 and iv2. Formula (3) is a formula for calculating the second current vector I2(u2, v2) when the motor M2 has three phases.

Here, I2d and I2q are the d-axis component and q-axis component of the second current vector I2 (u2, v2), and θ is a value obtained by converting the rotation angle detection value θ2 of the motor M2 into an electrical angle.

Current vector calculation section 510 calculates the magnitude |I2(u2, v2)| of the second current vector using equation (4).

In S740, the common sensor failure identifying unit 520 determines that the magnitude of the first current vector (|I1(u1,v1)|) and the magnitude of the second current vector (|I2(u2,v2)|) are substantially is equal to .

Here, the current detection values of the sensors S1-4 may contain errors. Therefore, the common sensor failure identification unit 520 determines that the difference between the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)| It may be determined whether it is within the range (±Δ _uv ). If the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)| proceed.

In S750, the common sensor failure identifying unit 520 determines that the difference between the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)| If it is within the error range (±Δ _uv ), the common sensor failure identification unit 520 identifies that the common sensor S5 has failed. The operation flow of this figure is based on the premise that the motor M1 and the motor M2 flow phase currents of substantially the same magnitude (amplitude). Assuming a single failure, there is a possibility that only one of the sensors S1 to 4 has failed, so the first current vector I1 (u1, v1 ) and the second current vector I2(u2, v2) calculated using the current detection values of the sensors S3 to S4 are correct. Therefore, when the magnitude of the first current vector I1 (u1, v1) and the magnitude of the second current vector I2 (u2, v2) are substantially equal, the first current vector I1 (u1, v1) and the second current vector I1 (u1, v1) It can be assumed that both of the two current vectors I2(u2,v2) are correct and sensors S1-4 are normal.

Therefore, if the failure detection unit 500 detects that one of the common sensor S5, at least one of the first motor phase sensors S1-2, and at least one of the second motor phase sensors S3-4 has failed. 7, the common sensor failure identification unit 520 identifies that the common sensor S5 has failed in S750, cancels the winding short circuit state of each motor, and ends the operation flow of FIG.

In S740, if the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)| to S760. In S760, the common sensor failure identification unit 520 diagnoses that one of the first motor phase sensors S1-2 and the second motor phase sensors S3-4 has failed.

According to the common sensor failure identification unit 520 described above, instead of providing individual current sensors for some phases of each motor, a common current sensor is provided for a phase pair selected one by one from each motor. However, such common current sensor failures can be identified.

Note that the common sensor failure identifying section 520 may make the determination in S740 using the first current vector I1 (u1, v1) and the second current vector I2 (u2, v2) at one point in time or at a plurality of points in time. Further, the common sensor failure identification unit 520 performs the determination in S740 based on the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)| may be performed using the average value over the time period.

In this operation flow, the common sensor failure identification unit 520 uses the result of comparison between the magnitude of the first current vector |I1(u1,v1)| and the magnitude of the second current vector |I2(u2,v2)| determines whether or not there is a failure in the common sensor S5. Therefore, the directions of the first current vector I1 (u1, v1) and the second current vector I2 (u2, v2) do not affect the determination. Therefore, current vector calculation unit 510 uses a predetermined fixed value instead of setting θ in equations (1) and (3) to a value based on rotation angle detection values θ1-2 by rotation angle sensors R1-2. (for example, 0°).

FIG. 8 shows an example of waveforms of phase currents flowing through the motors M1-M2. During normal operation, each driver 110 supplies phase current to each phase of each motor to drive each motor. When switching to the winding short-circuit state in S700 of FIG. 7, each driving unit 110 stops driving each motor. The phase current of each motor changes transiently for a while after the winding short circuit occurs. In S710, the common sensor failure identification section 520 waits for a sufficient period of time for the phase current to reach a steady state after the transient change in the phase current has ended. As a result, in S740, the common sensor failure identifying unit 520 accurately compares the magnitude of the first current vector |I1(u1, v1)| and the magnitude of the second current vector |I2(u2, v2)|. can do.

FIG. 9 shows the operation flow of the first sensor group failure diagnosis section 530 according to this embodiment. The first sensor group failure diagnosis unit 530, in response to the diagnosis that one of the first motor phase sensors S1-2 and the second motor phase sensors S3-4 has failed in the operation flow of FIG. The operation flow of this figure may be executed.

In S900, the first sensor group failure diagnosis unit 530 puts the plurality of motors M1 and M2 into the winding short-circuit state using the control signals SH1 and SH2, and waits until the induced voltage of the first motor M1 becomes equal to or lower than the upper limit value. . The first sensor group failure diagnosis unit 530 detects that the induced voltage of the motor M1 becomes equal to or less than the upper limit value in response to the rotation speed (the number of revolutions per unit time) of the motor M1 becoming equal to or less than a predetermined reference value. It can be judged that Alternatively, the first sensor group failure diagnosis unit 530 temporarily switches the motor M1 to the winding open state at predetermined intervals, and if the voltage between any of the phases is equal to or higher than the upper limit value, the winding short circuit state is detected. , it is possible to wait until the induced voltage of the motor M1 becomes equal to or less than the upper limit value. The first sensor group failure diagnosis section 530 may use the power supply voltage Vdc as the upper limit value.

In S910, the first sensor group failure diagnosis unit 530 opens the windings of the motor M1 while the windings of the motor M2 are short-circuited. When the motor M1 has its windings open, no current flows through the phases of the motor M1. Therefore, when the windings of the motor M1 are open, the common sensor S5 can detect the current iw2 flowing through the W phase of the motor M2.

In S920, the first sensor group failure diagnosis unit 530 detects the current detection values iu2, iv2, and iw12 of the common sensor S5 and the second motor phase sensors S3 to S4, respectively, while the plurality of phases of the motor M1 are open. (=iw2) is used to calculate the total amount of current (=iu2+iv2+iw2) flowing into the motor M2. First sensor group failure diagnosis section 530 determines whether or not the total amount of current flowing into motor M2 is substantially zero. The first sensor group failure diagnosis unit 530 detects that the total amount of current flowing into the motor M2 is substantially 0 when the total amount of current flowing into the motor M2 is within a predetermined error range from 0. It can be determined that there is

In S930, the first sensor group failure diagnosis unit 530 detects that the total amount of current flowing into the motor M2 is substantially zero (“Y” in S920). Common sensor S5 is diagnosed as normal. In this case, since a failure has been detected in one of the sensors S1-5, the first sensor group failure diagnosis section 530 diagnoses that one of the first motor phase sensors S1-2 has failed. In S940, the first sensor group failure diagnosis unit 530 detects that the total amount of current flowing into the motor M2 is not substantially 0 (“N” in S920), and the first motor phase sensors S1-2 are normal. Diagnosis is. In this case, since a failure is detected in one of the sensors S1-5, the first sensor group failure diagnosis unit 530 diagnoses that one of the sensors S3-5 has failed. Here, since it is diagnosed that one of the sensors S1 to S4 has failed in S760 of FIG. Diagnose.

According to the first sensor group failure diagnosis section 530 described above, the phase current of only the motor M2 can be measured using the common sensor S5 by putting the motor M1 in the winding open state. As a result, the first sensor group failure diagnosis section 530 can determine whether or not the sensors S3 to S5 used to calculate the total amount of current flowing into the motor M2 have failed. As a result, the first sensor group failure diagnosis section 530 can diagnose whether or not any of the first motor phase sensors S1 to S2, which measure only the phase current of the motor M1, has failed.

Note that the operation flow of FIG. 9 is not based on the premise that the plurality of motors M1 to M2 of the drive system 10 flow phase currents of substantially the same magnitude (amplitude). Therefore, the first sensor group failure diagnosis unit 530 measures only the phase current of the motor M1 using this operation flow even when each of the plurality of motors M1 to M2 independently drives different axes. It is possible to diagnose whether any one of the one-motor phase sensors S1-2 has failed.

Further, even when there are two or more common sensors, the first sensor group failure diagnosis unit 530 uses the operation flow shown in FIG. It may be diagnosed which sensor within the group of the two second motor phase sensors and the two or more common sensors has failed.

FIG. 10 shows the operation flow of the first sensor failure identifying section 540 according to this embodiment. The first sensor failure identification unit 540 executes the operation flow of FIG. 9 in response to the diagnosis that one of the first motor phase sensors S1-2 has failed in the operation flow of FIG. you can In the operation flow of FIG. 10, the first sensor failure identification unit 540 detects that the phase currents of substantially the same magnitude (amplitude) flow through the plurality of motors M1 to M2 of the drive system 10 as in the operation flow of FIG. As a prerequisite (although they may be out of phase), identify which of the first motor phase sensors S1 and S2 is failing.

In S1000, first sensor failure identifying section 540 uses control signals SH1 and SH2 to instruct driving sections 110-1 and 110-2 to place a plurality of motors M1 and M2 in the winding short circuit state. Motor M1 and motor M2 flow phase currents in which the magnitude difference between the first current vector and the second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuit state.

In S1010, the first sensor failure identifying section 540 waits for a predetermined period. As a result, the first sensor failure identifying section 540 waits until the phase currents of the motors M1 and M2 reach a steady state due to the winding short circuit.

In S1020, the first sensor failure identification unit 540 waits until the timing when the current flowing through the phase included in the phase pair among the plurality of second motor phases becomes 0 when the windings of the motors M1 to M2 are short-circuited. In this embodiment, the first sensor failure identifying section 540 waits for the timing when the current flowing through the W phase of the motor M2 becomes zero. Here, since the sum of the currents flowing through the phases of the motor M2 is 0, iu2+iv2+iw2=0. Therefore, the first sensor failure identification unit 540 waits for the timing when the sum of the current detection values of the second motor phase sensors S1 and S2 becomes 0 (for example, iu2+iv2=0 or iu2=-iv2). The timing at which the current iw2 flowing through the phase becomes 0 can be determined. The first sensor failure identification unit 540 may detect the timing at which the current iw2 flowing through the W phase of the motor M2 becomes 0 within a predetermined error range, for example, by detecting the zero crossing timing of iu2+iv2. . At the timing when the current iw2 becomes 0, the current detection value iw12 of the common sensor S5 can be considered equal to the current value of the W-phase current iw1 of the motor M1.

In S1030, the current vector calculation unit 510 calculates the current detection value iw12 of the common sensor S5 at the timing when it is determined that the current flowing through the phase included in the phase pair among the plurality of second motor phases becomes 0 and the current detection value iw12 of the first motor phase sensor. The current detection values iu1 and iv1 of S1-2 are used to calculate first current vectors for the number of first motor phase sensors S1-2. In this embodiment, the current vector calculator 510 uses the current detection value iw12 of the common sensor S5 and the current detection value iu1 of the first motor phase sensor S1 to calculate the magnitude |I1(iu1, iw12) of the first current vector. | is calculated. Further, the current vector calculation unit 510 uses the current detection value iw12 of the common sensor S5 and the current detection value iv1 of the first motor phase sensor S2 to calculate the magnitude |I1(iv1, iw12)| of the first current vector. do.

Here, the current vector calculation unit 510 calculates the first current vector I1 (iu1, iw12) is calculated. Further, the current vector calculation unit 510 calculates the first current vector I1 (iv1, iw12 ) is calculated. Current vector calculator 510 calculates magnitudes |I1(iu1, iw12)| and |I1(iv1, iw12)| of the first current vector in the same manner as in equation (2).

Further, current vector calculation unit 510 uses current detection values iu2 and iv2 of second motor phase sensors S3 to S4 to calculate the magnitude |I2(iu2, iv2)| Calculated by (4). Here, since the second motor phase sensors S3 to S4 are normal, the magnitude |I2(iu2, iv2)| of the second current vector may contain some error, but is a correct value.

In S1040, first sensor failure identifying section 540 selects second current vector I2 (iu2, iv2) among (I1 (iu1, iw12) and I1 (iv1, iw12)) of the first current vectors calculated in S1030. ) to determine the first current vector that has the greatest magnitude difference. In the present embodiment, the first sensor failure identification unit 540 determines the absolute difference between the magnitude of the first current vector |I1(iu1, iw12)| and the magnitude of the second current vector |I2(iu2, iv2)| and the absolute value of the difference between the magnitude of the first current vector |I1(iv1, iw12)| and the magnitude of the second current vector |I2(iu2, iv2)| Determine the first current vector such that

In S1050, the first sensor failure identification unit 540 determines the magnitude of the second current vector I2 (iu2, iv2) among the first current vectors (I1 (iu1, iw12) and I1 (iv1, iw12)). It is specified that the first motor phase sensor that outputs the current detection value used to calculate the first current vector with the maximum difference has failed. For example, the first sensor failure identification unit 540 determines ||I1(iu1, iw12)|-|I2(iu2, iv2)||>||I1(iv1, iw12)|-|I2(iu2, iv2)|| , the current detection value iu1 used for calculating the first current vector I1 (iu1, iw12) having the largest difference in magnitude from the second current vector I2 (iu2, iv2) is output. It can be determined that the 1-motor phase sensor S1 has failed.

Here, since the second current vector I2 (iu2, iv2) can be regarded as correct, on the premise that the plurality of motors M1 to M2 flow the same phase current, the magnitude of the first current vector is the magnitude of the second current vector I2 It should be substantially the same as the magnitude of (iu2, iv2). Therefore, the first sensor failure identifying section 540 can regard the current detection value used to calculate the first current vector that deviates in magnitude from the second current vector I2 (iu2, iv2) as an error. The first sensor failure identification unit 540 releases the winding short circuit state of the motors M1-2.

According to the first sensor failure identification unit 540 described above, each of the currents flowing through the phase provided with the common sensor S5 in the motor M2 in the winding short-circuit state of the motors M1 and M2 is determined to be 0. The current sensing values of sensors S1-5 can be used to identify which of the first motor phase sensors S1-2 has failed. The second sensor failure identification unit 550 uses the same operation flow as in FIG. 10, and is provided with a common sensor S5 in the motor M1 in the state of short-circuited windings of the motors M1 and M2 in the same manner as the first sensor failure identification unit 540. Which of the second motor phase sensors S3-4 is out of order can be identified using the current detection values of the sensors S1-5 at the timing when the current flowing through the phase is determined to be 0.

The drive control unit 120 detects that one of the sensors S1 to S5 has failed by the failure detection unit 500, and the common sensor failure identification unit 520, the first sensor group failure diagnosis unit 530, and the first sensor failure identification unit 540 and the second sensor failure identification unit 550 can identify which sensor is malfunctioning. Drive control unit 120 includes all of failure detection unit 500, common sensor failure identification unit 520, first sensor group failure diagnosis unit 530, first sensor failure identification unit 540, and second sensor failure identification unit 550. It doesn't have to be. The drive control unit 120 may have an arbitrary combination of some of these, and can identify or narrow down the faulty sensor within a range according to the configuration of the drive control unit 120 .

FIG. 11 shows the operation flow of the current vector calculator 510, the current command calculators 570-1 and 570-2, and the current controllers 580-1 and 580-2 according to this embodiment. In S<b>1100 , current vector calculation section 510 receives from common sensor failure identification section 520 the determination result of whether or not common sensor S<b>5 has a failure. Current vector calculation unit 510 receives from first sensor failure identification unit 540 the determination result of the presence/absence of failure of each of first motor phase sensors S1-2. Current vector calculation unit 510 receives from second sensor failure identification unit 550 the determination result of the presence/absence of failure of each of second motor phase sensors S3-4.

In response to detection of a failure in one of each of the first motor phase sensors S1-2 and each of the second motor phase sensors S3-4, the current vector calculation unit 510 calculates one of the detected failures. The current sensing values of the sensors are inferred using the current sensing values of the other sensors among the common sensor S5, each of the first motor phase sensors S1-2, and each of the second motor phase sensors S3-4. For example, when a failure of the first motor phase sensor S1 is detected, the current vector calculation unit 510 converts the current detection value iu1 of the sensor S1 to the current detection value iw12 of the sensor S5, the current detection value iv1 of the sensor S2, and the current detection value iv1 of the sensor S3. It is estimated using the current detection value iu2 and the current detection value iv2 of the sensor S4.

Here, the total current flowing into each of the motors M1-2 is 0, and the total current flowing into all the motors M1-2 is also 0 (iu1+iv1+iu2+iv2+iw12=0). Therefore, iu1=-iv1-iu2-iv2-iw12. Therefore, in response to the failure of sensor S1, current vector calculation unit 510 can estimate current detection value iu1 of sensor S1 using current detection values iv1, iu2, iv2, and iw12 of the other sensors. can.

Similarly, the current vector calculation unit 510 estimates the current detection value iv1 of the sensor S2 by iv1=-iu1-iu2-iv2-iw12, and calculates the current detection value iu2 of the sensor S3 as iu2=-iv2-iu1-iv1- iw12, and the current detection value iv2 of the sensor S4 can be estimated from iv2=-iu2-iu1-iv1-iw12. Accordingly, current vector calculation unit 510 can estimate the current detection value of any one of sensors S1 to S4 in response to failure. It should be noted that current vector calculation section 510 calculates each first motor phase The current sensing value of any one of the sensors and each second motor phase sensor that has failed can be inferred.

In S1110, current vector calculation unit 510 uses the current detection values or estimated current detection values (iu1 and iv1) of the first motor phase sensors S1 and S2 and the rotation angle detection value θ1 to perform drive control of motor M1. Detect the first current vector I1 used for . The current vector calculator 510 may convert the rotation angle detection value θ1 into an electrical angle θ and calculate the first current vector I1=(I1d, I1q) using Equation (1).

In S1120, the current vector calculation unit 510 uses the current detection values (or estimated current detection values) iu2 and iv2 of the second motor phase sensors S3 to S4 and the rotation angle detection value θ2 to perform drive control of the motor M2. Detect a second current vector I2 used for . The current vector calculator 510 may convert the rotation angle detection value θ2 into an electrical angle θ and calculate the second current vector I2=(I2d, I2q) using Equation (3).

In S1130, current command calculation unit 570-1 and current control unit 580-1 use first torque command value τ1 and first current vector I1=(I1d, I1q) to control driving of motor M1. Current command calculation unit 570-1 generates first current command value I1t=(I1td, I1tq) in vector format from rotation angle detection value θ1 and torque command value τ1 of motor M1. A current control unit 580-1 generates a first current vector I1, which is a current detection value obtained by converting a rotation angle detection value θ1 of the motor M1, a first current command value I1t, and a phase current detection value of the motor M1 into a rotating coordinate system. and generate the drive signals Gu1 to Gz1 so that the first current vector I1 approaches (or matches) the current command value I1t.

In S1140, current command calculation unit 570-2 and current control unit 580-2 use second torque command value τ2 and second current vector I2=(I2d, I2q) to control driving of motor M2. Current command calculation unit 570-2 generates second current command value I2t=(I2td, I2tq) in vector format from rotation angle detection value θ2 and torque command value τ2 of motor M2. A current control unit 580-2 generates a second current vector I2, which is a current detection value obtained by converting the rotation angle detection value θ2 of the motor M2, the second current command value I2t, and the phase current detection value of the motor M2 into a rotating coordinate system. and generate the drive signals Gu2 to Gz2 so that the second current vector I2 approaches (or matches) the current command value I2t.

As a result, the drive control unit 120 uses the result of estimating the current detection value of the sensor in which a failure has been detected among the first motor phase sensors S1-2 and the second motor phase sensors S3-4 to generate a plurality of It is possible to control the drive amounts of the plurality of first motor phases and the plurality of second motor phases of the plurality of motors M1 and M2 by the driving units 110-1 and 110-2. Therefore, the drive control unit 120 can continue to drive the motors M1-M2 even if one of the sensors S1-5 fails.

Note that the drive control unit 120 may not have the function of identifying which of the plurality of sensors S1 to S5 has failed. In this case, the drive control unit 120 receives designation of the failed sensor from the user or another device, estimates the current detection value of the failed sensor, and uses the estimated current detection value to determine the driving amounts of the plurality of motors. You can control it.

FIG. 12 shows a partial configuration of a drive control section 1220 according to a modification of this embodiment. Drive control unit 1220 does not have common sensor failure identification unit 520 in drive control unit 120 of FIG. 5, but has second sensor group failure diagnosis unit 1200 . Drive control section 1220 detects the presence or absence of a failure in common sensor S5 based on the diagnosis results of first sensor group failure diagnosis section 530 and second sensor group failure diagnosis section 1200 . In this figure, illustration of current vector calculator 510, current command calculators 570-1 and 570-2, and current controllers 580-1 and 580-2 is omitted. 5 are assigned to components in the drive control unit 1220 that have the same functions and configurations as those of the drive control unit 120, and description thereof will be omitted except for differences.

The first sensor group failure diagnosis section 530 is the same as the first sensor group failure diagnosis section 530 in FIG. In this embodiment, the drive control unit 1220 does not have the common sensor failure identification unit 520, so the first sensor group failure diagnosis unit 530 detects that one of the sensors has failed by the failure detection unit 500. Then, the operation flow of FIG. 9 is executed in a state where it is unknown whether or not the common sensor S5 has failed. As a result, the first sensor group failure diagnosis unit 530 determines that the total amount of current flowing into the motor M2 is substantially 0 (predetermined from 0) while the plurality of first motor phases of the motor M1 are open. ("Y" in S920), the second motor phase sensors S3-4 and the common sensor S5 are diagnosed as normal (S930). The first sensor group failure diagnosis unit 530 checks that the total amount of current flowing into the motor M2 is not substantially zero (within a predetermined error range from 0) while the plurality of first motor phases of the motor M1 are open. outside) ("Y" in S920), it is diagnosed that one of the second motor phase sensors S3-4 and the common sensor S5 has failed (S930).

Similarly to the first sensor group failure diagnosis unit 530, the second sensor group failure diagnosis unit 1200 puts the motor M1 in the winding short-circuit state and opens the plurality of second motor phases of the motor M2. The first motor phase sensors S1-2 and the common sensor S5 are diagnosed as normal when the total amount of current flowing is substantially 0 (within a predetermined error range from 0). The second sensor group failure diagnosis unit 1200 checks that the total amount of current flowing into the motor M1 is not substantially zero (within a predetermined error range from 0) while the plurality of second motor phases of the motor M2 are open. outside), it is diagnosed that one of the first motor phase sensors S1-2 and the common sensor S5 has failed.

When it is diagnosed that the second motor phase sensors S3-4 and the common sensor S5 are normal and one of the first motor phase sensors S1-2 and the common sensor S5 is diagnosed as malfunctioning, the Current vector calculation unit 510, first sensor failure identification unit 540, and second sensor failure identification unit 550 can determine that one of first motor phase sensors S1-2 has failed. Further, when it is diagnosed that one of the second motor phase sensors S3-4 and the common sensor S5 has failed, and that one of the first motor phase sensors S1-2 and the common sensor S5 has failed, drive control is performed. Current vector calculation unit 510, first sensor failure identification unit 540, and second sensor failure identification unit 550 in unit 120 can determine that common sensor S5 has failed. Further, when it is diagnosed that one of the second motor phase sensors S3-4 and the common sensor S5 is faulty, and the first motor phase sensors S1-2 and the common sensor S5 are diagnosed to be normal, the drive control unit 120 Current vector calculation section 510, first sensor failure identification section 540, and second sensor failure identification section 550 can determine that any of second motor phase sensors S3 to S4 has failed.

According to the second sensor group failure diagnosis unit 1200 described above, it is possible to determine whether or not the common sensor S5 has failed without the common sensor failure identification unit 520 shown in FIG. Therefore, in the drive system 10 including the second sensor group failure diagnosis section 1200, it is not assumed that the plurality of motors M1-2 flow phase currents of substantially the same magnitude (amplitude). drive different axes independently, it is possible to determine whether or not the common sensor S5 is faulty.

Various embodiments of the invention may be described with reference to flowchart illustrations and block diagrams, where blocks refer to (1) steps in a process in which operations are performed or (2) devices responsible for performing the operations. may represent a section of Certain steps and sections may be implemented by dedicated circuitry, programmable circuitry provided with computer readable instructions stored on a computer readable medium, and/or processor provided with computer readable instructions stored on a computer readable medium. you can Dedicated circuitry may include digital and/or analog hardware circuitry, and may include integrated circuits (ICs) and/or discrete circuitry. Programmable circuits include logic AND, logic OR, logic XOR, logic NAND, logic NOR, and other logic operations, memory elements such as flip-flops, registers, field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), etc. and the like.

Computer-readable media may include any tangible device capable of storing instructions to be executed by a suitable device, such that computer-readable media having instructions stored thereon may be designated in flowcharts or block diagrams. It will comprise an article of manufacture containing instructions that can be executed to create means for performing the operations described above. Examples of computer-readable media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer readable media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory), Electrically Erasable Programmable Read Only Memory (EEPROM), Static Random Access Memory (SRAM), Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD), Blu-ray (RTM) Disc, Memory Stick, Integration Circuit cards and the like may be included.

The computer readable instructions may be assembler instructions, Instruction Set Architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or instructions such as Smalltalk, JAVA, C++, etc. any source or object code written in any combination of one or more programming languages, including object-oriented programming languages, and conventional procedural programming languages such as the "C" programming language or similar programming languages; may include

Computer readable instructions may be transferred to a processor or programmable circuitry of a general purpose computer, special purpose computer, or other programmable data processing apparatus, either locally or over a wide area network (WAN), such as a local area network (LAN), the Internet, or the like. ) and may be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

FIG. 13 illustrates an example computer 2200 upon which aspects of the invention may be implemented in whole or in part. Programs installed on the computer 2200 may cause the computer 2200 to function as one or more sections of an operation or apparatus associated with an apparatus according to embodiments of the invention, or may Sections may be executed and/or computer 2200 may be caused to execute processes or steps of such processes according to embodiments of the present invention. Such programs may be executed by CPU 2212 to cause computer 2200 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

Computer 2200 according to this embodiment includes CPU 2212 , RAM 2214 , graphics controller 2216 , and display device 2218 , which are interconnected by host controller 2210 . Computer 2200 also includes input/output units such as communication interface 2222, hard disk drive 2224, DVD-ROM drive 2226, and IC card drive, which are connected to host controller 2210 via input/output controller 2220. there is The computer also includes legacy input/output units such as ROM 2230 and keyboard 2242 , which are connected to input/output controller 2220 through input/output chip 2240 .

CPU 2212 operates according to programs stored in ROM 2230 and RAM 2214, thereby controlling each unit. Graphics controller 2216 retrieves image data generated by CPU 2212 into itself, such as a frame buffer provided in RAM 2214 , and causes the image data to be displayed on display device 2218 .

Communication interface 2222 communicates with other electronic devices over a network. Hard disk drive 2224 stores programs and data used by CPU 2212 within computer 2200 . DVD-ROM drive 2226 reads programs or data from DVD-ROM 2201 and provides programs or data to hard disk drive 2224 via RAM 2214 . The IC card drive reads programs and data from IC cards and/or writes programs and data to IC cards.

ROM 2230 stores therein programs that are dependent on the hardware of computer 2200, such as a boot program that is executed by computer 2200 upon activation. Input/output chip 2240 may also connect various input/output units to input/output controller 2220 via parallel ports, serial ports, keyboard ports, mouse ports, and the like.

A program is provided by a computer-readable medium such as a DVD-ROM 2201 or an IC card. The program is read from a computer-readable medium, installed in hard disk drive 2224 , RAM 2214 , or ROM 2230 , which are also examples of computer-readable medium, and executed by CPU 2212 . The information processing described within these programs is read by computer 2200 to provide coordination between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing the manipulation or processing of information in accordance with the use of computer 2200 .

For example, when communication is performed between the computer 2200 and an external device, the CPU 2212 executes a communication program loaded into the RAM 2214 and sends communication processing to the communication interface 2222 based on the processing described in the communication program. you can command. The communication interface 2222 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as the RAM 2214, the hard disk drive 2224, the DVD-ROM 2201, or an IC card under the control of the CPU 2212, and transmits the read transmission data. Data is transmitted to the network, or received data received from the network is written to a receive buffer processing area or the like provided on the recording medium.

In addition, the CPU 2212 causes the RAM 2214 to read all or necessary portions of files or databases stored in external recording media such as a hard disk drive 2224, a DVD-ROM drive 2226 (DVD-ROM 2201), an IC card, etc. Various types of processing may be performed on the data in RAM 2214 . CPU 2212 then writes back the processed data to the external recording medium.

Various types of information, such as various types of programs, data, tables, and databases, may be stored on recording media and subjected to information processing. CPU 2212 performs various types of operations on data read from RAM 2214, information processing, conditional decision making, conditional branching, unconditional branching, and information retrieval, as specified throughout this disclosure and by instruction sequences of programs. Various types of processing may be performed, including /replace, etc., and the results written back to RAM 2214 . In addition, the CPU 2212 may search for information in a file in a recording medium, a database, or the like. For example, if a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 2212 determines that the attribute value of the first attribute is specified. search the plurality of entries for an entry that matches the condition, read the attribute value of the second attribute stored in the entry, and thereby associate it with the first attribute that satisfies the predetermined condition. an attribute value of the second attribute obtained.

The programs or software modules described above may be stored in a computer readable medium on or near computer 2200 . Also, a recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable medium, thereby providing the program to the computer 2200 via the network. do.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The execution order of each process such as actions, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is particularly "before", "before etc., and it should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if the description is made using "first," "next," etc. for the sake of convenience, it means that it is essential to carry out in this order. not a thing

10 drive system 100 motor drive device 110-1~2 drive unit 120 drive control unit 200-1~2 short circuit control unit 210-1~2 gate driver 300 conductor 310 magnetic core 320 magnetic sensor 400 first conductor 405 second conductor 410 magnetic core 420 magnetic sensor 500 failure detection unit 510 current vector calculation unit 520 common sensor failure identification unit 530 first sensor group failure diagnosis unit 540 first sensor failure identification unit 550 second sensor failure identification unit 570-1 to 2 current Command calculation units 580-1 and 580-2 Current control unit 1200 Second sensor group failure diagnosis unit 1220 Drive control unit 2200 Computer 2201 DVD-ROM
2210 host controller 2212 CPU
2214 RAM
2216 graphics controller 2218 display device 2220 input/output controller 2222 communication interface 2224 hard disk drive 2226 DVD-ROM drive 2230 ROM
2240 input/output chip 2242 keyboard

Claims (11)

a first drive unit that drives a plurality of first motor phases of the first motor;
a second drive unit that drives a plurality of second motor phases of the second motor;
a common sensor for detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases;
at least one first motor phase sensor that detects a current flowing through each phase of the plurality of first motor phases that is not included in the phase pair;
at least one second motor phase sensor that detects a current flowing through each phase of the plurality of second motor phases that is not included in the phase pair;
The current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor are used to determine the plurality of second motor phase sensors by the first driving section and the second driving section. a drive control unit that controls drive amounts of one motor phase and the plurality of second motor phases ,
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit
A total amount of current flowing into the first motor and the second motor calculated using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor is outside a predetermined error range from 0, a failure detection unit that detects that any sensor has failed;
A failure is detected in any one of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor, and the windings of the first motor and the second motor The first current vector calculated using the current detection values of the at least one first motor phase sensor and the second current vector calculated using the current detection values of the at least one second motor phase sensor in a short circuit state. and a common sensor failure identification unit that identifies that the common sensor has failed according to the fact that the difference between the magnitudes of and is within a predetermined error range
A motor drive device having a a first drive unit that drives a plurality of first motor phases of the first motor;
a second drive unit that drives a plurality of second motor phases of the second motor;
a common sensor for detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases;
at least one first motor phase sensor that detects a current flowing through each phase of the plurality of first motor phases that is not included in the phase pair;
at least one second motor phase sensor that detects a current flowing through each phase of the plurality of second motor phases that is not included in the phase pair;
The current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor are used to determine the plurality of second motor phase sensors by the first driving section and the second driving section. a drive control unit that controls drive amounts of one motor phase and the plurality of second motor phases;
with
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit is
the plurality of second motors in a winding short circuit condition of the first motor and the second motor in response to the diagnosis that any one of the at least one first motor phase sensor has failed; At least 1 using the current detection value of the common sensor and the current detection value of each of the at least one first motor phase sensors at the timing when it is determined that the current flowing in the phase included in the phase pair becomes 0 a current vector calculation unit that calculates two first current vectors;
of the at least one first current vector that has the largest difference in magnitude from the second current vector calculated using the current detection values of the at least one second motor phase sensor; a first sensor failure identification unit that identifies that the first motor phase sensor that outputs the current detection value used for the calculation has failed;
A motor drive device having a In response to detection of a failure of one of the at least one first motor phase sensor and the at least one second motor phase sensor, the drive control unit controls the one of the at least one first motor phase sensor and the at least one second motor phase sensor. using a result of estimating a current detection value of a sensor using current detection values of other sensors among the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor; 3. The motor driving device according to claim 1, wherein the driving amounts of the plurality of first motor phases and the plurality of second motor phases by the first driving section and the second driving section are controlled. The drive control unit calculates the first motor and the second motor using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor. 4. The device according to any one of claims 1 to 3, further comprising a failure detection unit that detects that any of the sensors has failed when the total amount of current flowing into the sensor is outside the range of 0 to a predetermined error. A motor drive as described. The drive control unit calculates the first motor phase using current detection values of the common sensor and the at least one second motor phase sensor in a state in which the plurality of first motor phases of the first motor are open. a first sensor group failure diagnosis unit for diagnosing that the at least one second motor phase sensor is normal when the total amount of current flowing into the two motors is within a predetermined error range from 0; 5. The motor drive device according to claim 4, comprising: The drive control unit calculates the current detection value of each of the common sensor and the at least one first motor phase sensor while the plurality of second motor phases of the second motor are open. a second sensor group failure diagnosis unit for diagnosing that the at least one first motor phase sensor is normal when the total amount of current flowing into the two motors is within a predetermined error range from 0; The motor drive device according to claim 5, comprising: the plurality of first motor phases are three first motor phases;
the plurality of second motor phases are three second motor phases;
The number of common sensors is one,
the at least one first motor phase sensor is two first motor phase sensors;
7. A motor drive device according to any preceding claim, wherein the at least one second motor phase sensor is two second motor phase sensors. the first drive unit driving a plurality of first motor phases of the first motor;
a second drive unit driving a plurality of second motor phases of the second motor;
a common sensor detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases;
at least one first motor phase sensor respectively detecting current flowing through each phase of the plurality of first motor phases not included in the phase pair;
at least one second motor phase sensor respectively detecting current flowing through each phase of the plurality of second motor phases not included in the phase pair;
A drive control section controls the first drive section and the second drive section using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor. controlling the drive amounts of the plurality of first motor phases and the plurality of second motor phases by
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit
A total amount of current flowing into the first motor and the second motor calculated using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor is outside a predetermined error range from 0, detecting that one of the sensors has failed;
A failure is detected in any one of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor, and the windings of the first motor and the second motor The first current vector calculated using the current detection values of the at least one first motor phase sensor and the second current vector calculated using the current detection values of the at least one second motor phase sensor in a short circuit state. is within a predetermined error range, determining that the common sensor has failed . the first drive unit driving a plurality of first motor phases of the first motor;
a second drive unit driving a plurality of second motor phases of the second motor;
a common sensor detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases;
at least one first motor phase sensor respectively detecting current flowing through each phase of the plurality of first motor phases not included in the phase pair;
at least one second motor phase sensor respectively detecting current flowing through each phase of the plurality of second motor phases not included in the phase pair;
A drive control section controls the first drive section and the second drive section using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor. controlling the drive amounts of the plurality of first motor phases and the plurality of second motor phases by
with
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit is
the plurality of second motors in a winding short circuit condition of the first motor and the second motor in response to the diagnosis that any one of the at least one first motor phase sensor has failed; At least 1 using the current detection value of the common sensor and the current detection value of each of the at least one first motor phase sensors at the timing when it is determined that the current flowing in the phase included in the phase pair becomes 0 calculating two said first current vectors;
of the at least one first current vector that has the largest difference in magnitude from the second current vector calculated using the current detection values of the at least one second motor phase sensor; Identify that the first motor phase sensor that outputs the current detection value used for the calculation has failed
Motor drive method. executed by a computer, said computer comprising:
a first drive unit that drives a plurality of first motor phases of the first motor;
a second drive unit that drives a plurality of second motor phases of the second motor;
a common sensor for detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases; at least one first motor phase sensor for detecting current flowing in each phase not included in the phase pair; and at least one second motor phase sensor for detecting current flowing in each phase of the plurality of second motor phases not included in the phase pair. a drive control unit that controls amounts of driving the plurality of first motor phases and the plurality of second motor phases by the first driving unit and the second driving unit, using respective current detection values of motor phase sensors; to make it work ,
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit
A total amount of current flowing into the first motor and the second motor calculated using respective current detection values of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor is outside a predetermined error range from 0, a failure detection unit that detects that any sensor has failed;
A failure is detected in any one of the common sensor, the at least one first motor phase sensor, and the at least one second motor phase sensor, and the windings of the first motor and the second motor The first current vector calculated using the current detection values of the at least one first motor phase sensor and the second current vector calculated using the current detection values of the at least one second motor phase sensor in a short circuit state. and a common sensor failure identification unit that identifies that the common sensor has failed according to the fact that the difference between the magnitudes of and is within a predetermined error range
motor drive program. executed by a computer, said computer comprising:
a first drive unit that drives a plurality of first motor phases of the first motor;
a second drive unit that drives a plurality of second motor phases of the second motor;
a common sensor for detecting a total current flowing through a phase pair selected one by one from the plurality of first motor phases and the plurality of second motor phases; at least one first motor phase sensor for detecting current flowing in each phase not included in the phase pair; and at least one second motor phase sensor for detecting current flowing in each phase of the plurality of second motor phases not included in the phase pair. a drive control unit that controls amounts of driving the plurality of first motor phases and the plurality of second motor phases by the first driving unit and the second driving unit, using respective current detection values of motor phase sensors;
to make it work,
Phase currents of the first motor and the second motor in which a difference in magnitude between a first current vector and a second current vector obtained by converting the respective phase currents is within a predetermined error range in a winding short-circuited state. and
The drive control unit is
the plurality of second motors in a winding short circuit condition of the first motor and the second motor in response to the diagnosis that any one of the at least one first motor phase sensor has failed; At least 1 using the current detection value of the common sensor and the current detection value of each of the at least one first motor phase sensors at the timing when it is determined that the current flowing in the phase included in the phase pair becomes 0 a current vector calculation unit that calculates two first current vectors;
of the at least one first current vector that has the largest difference in magnitude from the second current vector calculated using the current detection values of the at least one second motor phase sensor; a first sensor failure identification unit that identifies that the first motor phase sensor that outputs the current detection value used for the calculation has failed;
motor drive program.

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